Field of the Invention
The present invention relates to a cleaning device of a printing cylinder and, more particularly, to a cleaning device structured suitably for cleaning off paper powder and ink residues adhered to a blanket cylinder or the like by using a rotary brush.
A conventional device for cleaning the blanket cylinder by use of a rotary brush includes an opening formed in a box-like casing. The rotary brush is encased in the casing, with some portion thereof fronting from this opening. A brush roll is rotationally driven by a motor. The brush fronting from the opening rotationally contacts the blanket cylinder, whereby the paper powder and ink residues are scraped off from the cylinder surface by the brush. The casing encases a scraper which contacts the brush. The dusts adhered to the brush are removed and temporarily accommodated in the casing. Then, the bottom of the casing is opened every time the cleaning process has been finished or periodically, the dusts accommodated therein are abandoned.
The conventional method, however, presents such a problem that the dusts accommodated in the casing are, if left for a long time, adhered to the bottom of the casing because of the paper powder containing the ink and ink residues, resulting in a difficulty to clean the casing. It is therefore considered that the casing is frequently cleaned, or alternatively a forcible exhaust is effected by vacuum suction with a vacuum unit connected to the casing.
However, if the cleaning frequency increases as in the former case, this involves a stop of the printing operation and is not therefore realistic. In the latter case, though effective because of performing the continuous suction exhaust, it is required that a vacuum area be formed entirely within the elongate cleaning casing. In this case, a large-sized vacuum unit is needed. This is still an ineffective method.